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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

64 results found.

  1. IceCube Alert 251008A: Global MASTER-Net observations report
  2. GRB 251007B: SVOM/C-GFT upper limit
  3. EP250910a: Global MASTER-Net observations report
  4. GRB 250830C: AstroSat CZTI detection of a long burst
  5. Fermi GRB 250621A: Global MASTER-Net observations report
  6. GRB 250421B: AstroSat CZTI detection of a bright long burst
  7. LIGO/Virgo/KAGRA S250211aa: Updated Sky localization and EM Bright Classification
  8. Fermi trigger No 758442826: Global MASTER-Net observations report
  9. GRB 250101A: BOOTES-4/MET optical afterglow detection
  10. GRB 240809A: Swift/UVOT Detection
  11. Fermi GRB 240727A: Global MASTER-Net observations report
  12. GRB 240627A: AstroSat CZTI detection
  13. Konus-Wind detection of GRB 240607A
  14. EXO 0748-676: Swift-BAT refined analysis
  15. Trigger 1236151: Swift detection of EXO 0748-676
  16. Fermi GRB 240605A: Global MASTER-Net observations report
  17. GRB 240531A: AstroSat CZTI detection of a short burst
  18. GRB 240426A: AstroSat CZTI detection
  19. Fermi trigger No 709083929: Global MASTER-Net observations report
  20. GRB 230524B: AstroSat CZTI detection
  21. GRB 230427A: Swift/UVOT Detection
  22. GRB 221024A: Swift-XRT refined Analysis
  23. GRB 220702B: AstroSat CZTI detection
  24. GRB 220317A: Fermi GBM detection
  25. GRB 210330A: AstroSat CZTI detection
  26. Swift GRB 210318A: Global MASTER-Net observations report
  27. Fermi trigger No 636187116: Global MASTER-Net observations report
  28. GRB 210126A: AstroSat CZTI detection
  29. Fermi trigger No 630389391: Global MASTER-Net observations report
  30. Fermi trigger No 605756501: Global MASTER-Net observations report
  31. Fermi trigger No 600666048: Global MASTER-Net observations report
  32. Fermi trigger No 600448273: Global MASTER-Net observations report
  33. IceCube Alert 191215.47: Global MASTER-Net observations report
  34. LIGO/Virgo S190910d Global MASTER-Net observations report
  35. Konus-Wind observation of GRB 190206A
  36. GRB 161219B: POLAR Observation
  37. GRB 161108A: Swift/UVOT Upper Limits
  38. GRB 160408A: Swift/UVOT Upper Limits
  39. GRB 150627A: Swift/UVOT Detection
  40. GRB 150626A: Swift/UVOT Upper Limits
  41. Swift triggered on a source in Terzan 5 (trigger=637212)
  42. GRB 141130A: Mondy optical observations
  43. Konus-Wind observation of GRB 140906C
  44. SGR 1745-29 (Swift trigger 565443), Swift-BAT refined analysis
  45. GRB 110825A: Suzaku WAM observation of the prompt emission
  46. GRB 110205A: Suzaku WAM observation of the prompt emission
  47. GRB 101008A: Swift-BAT refined analysis
  48. GRB 101008A: Enhanced Swift-XRT position
  49. Konus-Wind observations of GRB 091010
  50. GRB090926B: Swift/UVOT Upper Limits
  51. GRB 090407: Swift UVOT Upper Limits
  52. Konus-Wind observation of GRB 081121
  53. Swift detection of AX J1749.1-2639
  54. Swift/UVOT observations of GRB080130
  55. Further Retractions of previous Swift-BAT triggers
  56. Retractions of previous Swift-BAT triggers
  57. GRB 060813: A long, bright GRB detected with Suzaku WAM
  58. GRB 060515: Super-LOTIS Observations
  59. GRB 050525, spectral lag pseudo-redshift
  60. GRB 050128: Swift XRT prompt afterglow position
  61. IPN confirmation of the reactivation of SGR1900+14
  62. GRB 990123: Reduced HST Images
  63. GRB 990123: Updated Keck Spectroscopy Results
  64. GRB980329 VLA observations

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